Depression associated with dementia with Lewy bodies (DLB) and the effect of somatotherapy

Dementia with Lewy bodies is associated with higher scores on the Geriatric Depression Scale than is Alzheimer's disease

BACKGROUND

Several reports suggest a higher morbidity of depression in patients with dementia with Lewy bodies (DLB) than in patients with Alzheimer's disease (AD). However, these results have not been duplicated consistently. The psychiatric symptoms of dementia, including depression, are important for its diagnosis and management. Thus, the aim of the present study was to clarify the characteristics of the depressive symptoms in DLB compared with AD using the Geriatric Depression Scale (GDS).

METHODS

We examined the GDS score for 86 patients with probable DLB (based on the Consensus Criteria for the clinical diagnosis of DLB) and 86 patients with probable AD (based on criteria of the National Institute for Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association), who were matched according to age, sex, education, and Mini-Mental State Examination (MMSE) scores. We also examined correlations between GDS scores and age, sex, or MMSE scores in both groups. Correlations between GDS scores and metaiodobenzylguanidine (MIBG) scintigraphy were examined in patients with DLB. To characterize the GDS in DLB, its profile was examined using factor structures.

RESULTS

Scores for DLB patients were twice as high on the GDS as those for AD patients. There was no correlation between GDS score and age, sex, or MMSE scores in either group. Furthermore, there was no correlation between the results of MIBG scintigraphy and GDS scores in the DLB group. Using factor structures, the depression symptom profile of these diseases suggested that depression-specific symptoms, such as mood, worry, or future outlook, were more frequent in the DLB group than non-specific symptoms, such as lack of energy, decreased concentration, or apathy.

CONCLUSIONS

The data suggest that depressive symptoms are highly specific symptoms of DLB, independent of other features of this disorder. The GDS could be used as a subsidiary tool in differentiating DLB from AD and is more useful than clinical observations of depression.

Dementia in Parkinson's disease

OPINION STATEMENT

Dementia in Parkinson's disease encompasses a spectrum relating to motor, psychiatric, and cognitive symptoms that are classified as either Dementia with Lewy Bodies (DLB) (initial cognitive symptoms) or Parkinson's Disease Dementia (PDD) (initial motor signs preceding cognitive symptoms by at least a year). Anticholinergic and antipsychotic drugs have a high risk of adverse cognitive and/or motor effects, so their use should be minimized or avoided. Neuroleptic sensitivity is a severe psychomotor adverse reaction that is particularly associated with potent dopamine-blocking agents such as haloperidol. It occurs in up to 50% of individuals with PDD or DLB. Mild psychotic symptoms should first be addressed by reducing anticholinergic and/or dopaminergic agents, if possible. Patients with psychotic symptoms that threaten the safety of the patient or caregiver may benefit from treatment with quetiapine or, in refractory cases, clozapine. Cholinesterase inhibitors as a drug class have been shown to have beneficial effects on cognition in DLB and PDD, and may help to alleviate some psychiatric symptoms, such as apathy, anxiety, hallucinations, and delusions. Memantine may help to moderate cognitive symptoms in DLB and PDD, although current data suggest a more variable response, particularly in PDD. Parkinsonian motor signs that are accompanied by clinically significant cognitive impairment should be treated with carbidopa/levodopa only, as dopamine agonists and other antiparkinsonian medications generally carry a higher risk of provoking or exacerbating psychotic symptoms. Excessive daytime sleepiness and REM sleep behavior disorder are common associated features of PDD and DLB. Minimizing sedating medications during the day and promoting nocturnal sleep may help the daytime sleepiness; melatonin, clonazepam, gabapentin, and possibly memantine may be useful in treating REM sleep behavior disorder. Orthostatic hypotension can be managed with various nonpharmacologic interventions, and if needed, fludrocortisone and pyridostigmine. Midodrine should be used cautiously, if at all.